Thursday, March 1, 2012

Visualizing a nanosecond

We’re so glad to have run across this video where [Rear Admiral Grace Hopper] explains how to visualize a nanosecond. Now we had never heard of [Grace Hopper] before, but once you watch the clip (also embedded after the break) you’ll want to know who this person is. We work with divisions of seconds all the time when developing with microcontrollers. But those concepts are so abstract we never had a need to think about them as a physical distance. After all they’re a measure of time, right?

You can’t make it out, but she’s holding a length of wire between her hands. It is 11.8 inches long and represents how far electricity can travel in one nanosecond (one billionth of one second). She goes on to explain that this is a calculation of the distance which light can travel in one nanosecond, then really hits the concept home when she uses it to explain latency in satellite communications. For us, the waste of not putting a chip into sleep mode when it’s just stuck in the loop waiting for an interrupt is where we made the connection.

So back to the woman herself. We think you’ll really enjoy reading through her Wikipedia biography page. [Grace] was a computer science pioneer. She is credited with writing the very first computer compiler. She postulated and articulated the concepts that led to the development of COBOL, and popularized the term ‘debugging’. In short, she is one of the giants whose shoulders we all stand upon.